Traditional high-voltage MOSFET models include parasitic source-bulk and drain-bulk diode models. However, these models are simplified diode models and lack some of the more detailed aspects of p-n junctions diodes such as breakdown voltage, advanced leakage current, advanced temperature, and forward resistance are not modeled in any industry standard MOSFET model. Additionally, even industry standard diode models do not contain more advanced features such as reverse recovery. In many application circuits with inductive and capacitive loads, such as buck and boost converters, the output transistors are very large and circuit operation pushes these transistors to forward bias the drain-body diode during each switching cycle. Traditionally, the large MOSFETs were stand-alone external transistors which can be modeled as discrete devices so certain body diodes effects can be included. As HVMOS processes advance and the large power transistors become integrated into a single chip, it is necessary to produce large scalable devices which include more advanced properties that are critical to power circuit performance. We have shown that proper modeling of the drain-body diode including the reverse recovery effect gives a better prediction of power output and conversion efficiency. In this paper, we will present high-voltage MOSFETs model which includes industry standard BSIM3v3 and HiSIM-LDMOS models with an integrated diode model which includes advanced diode properties and dynamic reverse recovery modeling.